Pneumatic concentrating-table.



G. Q. PAYNE. PNEUMATIG CONGENTRATING TABLE.

APPLICATION FILED AUG.14, 1912.

4W: :w51 .w y r ffl/@Mures *o (Lau/w? gli? cmnncn e. aYNE, on NEW Your.,N. Y.

mamario concnnrnarmaraam Specilication of Letters Patent. applica/nonmea august 14, 191e. semi no. 71am.

Patented july 22, 1913.

To all wlzbm may concern e it known that l, CLARENCE Q. PAYNE,

a citizen of the United States et America, residing in the boroufgh ofManhattan, city,

county, and State o New York, have invented certain new and usefulImprovements in Pneumatic Concentrating-Tables,-

of which the following is a lull and true description.

My invention relates to improvements in that type ol concentrating tablewhich sepaby' air" under pressure, While being' subjected to lmechanicalagitation.

lt consists in the combination ol a novel' and improved form ettable-top With improved means for separating minerals of didere'ntspecilic gravities, alter they have been arranged in layers or strata bymeans' ol air pressure and mechanical agi-tation, upon the surface ofsaid table-top.

ile the pneumatic or dry table is able to secure goodresults inseparating minerals oit dierent specic gravities, especially altervcareful sizing, .its usefulness has heretofore been much-y retarded bythe diHiculty ol removing the separated products from the table in aclean condition after they have been arranged in distinct strata by theaction of air currents and mechanical agitation, and also by the lack ofdurability of the pervious table-top 1 upon which the separation ot theore-mixture takes place. v

ln an application led comcldent-ly,Wlthy this and bearing Serial No.715,006, filed August 1l, 1912, I have described and claimed a novelmedium for thepervious top of a pneumatic` concentrating table,-

whereby amore eicien't and satisfactmy separation is obtained than hasheretofore been possible.

In the accompanying illustration Figures l and 2 show in plan andsectional elevation, respectively, a concentrating table in which crosssection of the table top.l

In Figs. 1 and 2 the concentrating table is supported upon a foundationframe of channel-irons 10, by means of three levers and brackets 11,-1l. Two of these are placed at the head or feed-endeo the table, and oneat the discharge end, in ore der to secure a smooth reciprocatin motionfof the table Without disturbing vibrations due to unevenly loadedsupports. The iframe ol the table may be constructed `of channel-irons1Q. Below the frame of the f'tahle' is a' ll-'shaped sheet iron bottom13, ,With square ends'. This is closely riveted 5to` the, channel-'ironframe so as to make air-'tight joints.

rlhe table-top lll as shown in Figs'. 2 and 3 is composed of poroussilicd plates, 0r a? like minera-l septum, through' which air underpressure ismade to' pass'.v These plates @are cemented together a'ttheir joints, and' are held by light T irons 33 to the channel- 1irontrame of the table Their upper surifaces thus formth top orl deck ofthetable upon which the. separation takes place'. This form of table-topisshown' somewhat imo're clearly in vieW. Air is admitte to the underside of the concentrating table by means of a pipe 15;', which isconnected vvlth aV pressure fang," not shoWnv in the The table isgiven a4suitaable inclination' Y ,direction ci its len"hl,` so as to canse theslnoot-hiy' lengthwise, While it is given ,a shaking mot1on. Theinclination may be' varied@ by raising o r aweg embase of thevhimaged-lever which supports the lovverend of the table,but in generalthe inclination -Lwill not vary for the sameclass of material, and willybe merely suicient to permit'the different minerals composing yit tobecome `Well stratified as they travel down the table.

Any convenient t liead-'motionl mecha-l Fig. 3,- by a cross. sectionalfmaterial fed upon t= e upper end to travel' 4my invention is embodied.Fig. 3 shows af nism may be employed, such as that shown nected tothetable by means of the connecting-rod 21. To absorb the shock of the`rapid reversal of the table, a spiral spring 32 is so placed betweenthe angle-lever and a fixed abutment at the upper end of the headmotionframe' as to form an extension of the connect-ing lever.' Thecompression" of the spiral spring can be varied by means of a suitablebolt and nuts 22. The amount of motion imparted to the table may also bevaried within certain limits by means of the screw adjustment 23, whichpermits the upper abutment of thef'toggle-lever 17 to be movedhorizontally. In general, the amount of motion given to the table willvary with the degree of fneness of the materials to be treated, but willusually amount to one half inch or one inch in total throw. The speed ofthe table, or number of shakes per minute, will vary in general between200 and 300.

The table is fed atl its upper end, and for its full width, in anyconvenient manner as shown in Fig. 2 by a feed-hopper 24, with a gateand feed roller. As the ore-mixture is caused to travel lengthwise ofthe table, the combined eect of the upward air-currents through the linepores or openings of the' table top, and the shaking mot-ion o-f thetable, causes the minerals of the ore-mixture to separate and to formdistinct strata, or layers, the heavy mineral forming the lower layer,while the light mineral forms the upper layer. Diagonal guides orbanking strips 30, 30, and 31, '31, may be employed to narrow andthicken the ore-sheet at intervals lengthwise of t-he t-able, in orderto assist in stratifying its minerals by increasing their agitation.These banking strips do not accomplish the same purpose as riiiies whichare commonly used with wet tables, and whose function is to aid theseparation by subdividing the ore-sheet. In my invention the separationis effected by mass action, and it is thus broadly distinguished fromthat accomplished by shaking tables which use water as a medium ofseparation. In the latter case the use of riiiies is of advantage.

At the lower end of the table diagonal guide-pieces 25, 25 may be soplaced as to appreciably narrow the discharge line of the ore-sheet.These guides serve to thicken the ore-sheet gradually up to. thedischarge point, and thus to permit the separation of the layers, orstrata, of dierent minerals to be conveniently made along superposedlevels, by means of the division plates 26, 26. The guides 25, 25, areextended in a parallel position a certain distance beyond the lower endof the table, and form, with a suitable bottoni, a trough which carriesthe separated ore well beyond the lower edge of the table. Thisdischarge-spout or trough hasthe eX- tension pieces 27, 27 attached toits sides, and these carry the movable division-plates 26,` 26, whichare superposed. The front edges o-f the plates 26, 26, may be raised andlowered by the screw bolts and nuts 28, 28, which are supported bv thebrackets 29, 29.

For purposes of illustrat-ion,'F ig. 2 shows Ain sectional view a layerof ore upon the table-top which contains a heavy mineral and a lightmineral, which have been'stratilied in layers by the air-currentspassing through the table-top,'a.nd by mechanical agitation due to theshaking motionvof the table. The position ofthe light gangue mineral isshown by the shaded section at the upper part of the ore-sheet, and theheavy mineral by the unshaded portion below it. In order to remove cleanconcentrate and tailing from the table, the positions of thedivision-plates are so' adjusted that the dividing line between the twomineral strata falls between the upper and lower `division-plates. Thisspace may be varied, and it pei/'mits compensation to be made forirregularities in the ore composition and in feeding. The productremoved between the two division-plates constitutes a middling. Thatremoved below the lower division-plate is the concentrate, or heavymineral, while thatremoved above the upper division-plate is thetailing, or light mineral. The separat-ion of the various products isthus made along superposed levels. The

products of the separation are propelled forward by the shaking motionof the table, and are collected in separate chutes as indicated in Fig.2. then returned to the same or a separate table for re-treat-ment. Itthus becomes possible by means of superposed discharge openings, asdescribed, to remove clean separated products from the table, and at thesame time to maintain a large capacity of treatment.

The operation of my table is as follows: Air from a pressure fan isconveyed through the pipe 15 to the air boX 13 below the table, and isthen allowed to pass through the pervious table-top under a regulatedpressure. t the same time, the table is given a rapid reciprocatingmotion by-means of `the headmotion mechanism, driven by a belt from anoutside source of power. rThe material to be separated is fed in a drystate in a regulated stream from the hopper 24 across the full widthl ofthe table-top la. Where the porous The middling product may beV `theparticles to a predetermined ratio. This ratio will depend upon thediference in speciiic gravity between the heavy and light minerals inthe ore-mixture Which'is to be separated. The greater the diierence inspecilic gravity between minerals, the less. closely need the materialbe sized before separation, and vice versa. While traveling down theinclined surface of the table, the combined action of the upward aircurrents and the mechanical agitation of the particles, due to theshaking motion of the table, causes the heavier particles to settlethrough the agitated mass, and torni the bottom layer of the ore-sheetresting `on the table-top. 'lhe lighter particles, on the other hand,work their way upward and form the top layer of the ore-sheet, asindicated approximately in cross section in Fig 2. As fthe stratifiedminerals reach the lower end of the table, they encounter the guidepieces 25, 25, which narrow, and correspondingly thicken, the ore-sheetat its discharge end. this way the dividing line between the concentrateand tailing is made comparatively short, and by removing a smallamountot middling product at the junction las between the strata, alarge amount of clean concentrate and clean tailing can be removed bymeans of the superposed division plates, whose positions can beaccurately adjusted. 'lhe middling product may be retreated upon thesame or a separate table after a preliminary crushing, which isnecessary, in case the product contains a large amount of true middling,z". e., attached particles which require further crushing to unlockthem. In case the ore-mixture contains more `than two minerals to beSeparated, it is tpossible to employ three or more ,division plates, orpreferably to collect two of the minerals in a single group as a firststep, and then reseprate the group upon :i separate table.

y invention is clearly distinguished from that type of pneumaticconcentrating table inwhich thediiferent minerals are separated afterbeing stratified, by spreading them outin thin bands upon the surface ofa transversely .inclined table', and which are discharged atd/ierentpositions along the end and lower side of the table.

`-It is also distinguished from that type of 'tion of the ore-mixture.

'separate the stratit careful adjustment in order to obtain good resultsin separation, for the reason that the division plane between theconcentrate and tai-ling occupies -a wide'space on the table, and itsposition may be easily shifted owing to slightirregularitiesinoperation. By my i invention, on the contrary, 'the length of thedivision plane between the concentrate and tailing can be Vmadeextremely short, and its position can be maintained undisturbed withonly a slight amount of vertical shifting duc to variations in thecomposilt is possible in this way to remove the separated products froma pneumatic concentrating table in a cleaner condition after they havebeen stratified than has heretofore been possible.

Having thus described my invention, Iy

claim:

lnIn a pneumatic concentrating table, a table-top porous to air underpressure, consisting of a plate of accreted mineral particles forming amineral septum, in combination with means for feeding the material to beseparated upon said table-top, means for passing air through saidmineral scptum, means forreciprocating said table-top= and means forseparating the stratified minerals contained the material alongsuperposed levels, substantially as described.

2. In a pneumatic concentrating table, a table-top porous to air underpressure, con- .sisting of a plate of accreted mineral particles forminga mineral septum, in combiv nation with means for feeding the materialto be separated upon said table-top, means for passing air through saidmineral scptum, means for reciprocating said table-top, guides placeddiagonally to the line of travel of the feed-sheet along the table-topto thicken said sheet at its discharge point, and division plates alonsuperposed levels to minerals contained in the material, substantiallyvas described.

3. In a pneumatic concentrating table, a table-top consisting of amineral septum porous to air under preure, in-combination with means forreciprocating said table-top whilein an inclined positlon, means forfeeding the material to bevseparatcd upon said table-top, means forpassing air through ,along the table-top, and division plates alongrsuperposed levels at the/ dischargev vedge of the table-top to removethe separated minerals contained in the crude material, substantially asdescribed.`

4. In a pneumatic concentrating table, a

A table4top porous to air under pressure, consisting of platesofaocretcd mineralY particles forming the-top of an inclosed box, in

'combination with means' for passing airy from said boxthrough theporous mineral the stratified minerals contained in the Ina,-

tab'le-top, meanls o reci'nocacingrl said1 bo terial, substantially asdescribed.

W 11 e 1n an inc lne posi lon, u1 es p ace diagonally to the line oftravegl of the feed CLARENCE Q' PAYNE' 5 sheet along the table-top tothicken said Witnesses:

sheet at its ldischarge point, and division WALTER S. JONES,

plates along superposedk levels to separate OLIVER M. PENNINGTON.

